1. Technical Field
The present invention relates to a gas compressor, and in particular, to an improvement in a gas compressor of a vane rotary type.
2. Background Art
An air conditioning system conventionally uses a gas compressor that compresses a gas such as a refrigerant gas to be circulated in the air conditioning system.
The gas compressor is configured such that a compressor body that is driven for rotation to compress the gas is accommodated in a housing, a discharge chamber to which a high-pressure gas is discharged from the compressor body is defined to be formed, and the high-pressure gas is discharged from the discharge chamber to an outside of the housing.
A so-called vane rotary type gas compressor is known as an example of this gas compressor.
The gas compressor of this vane rotary type is configured such that a compressor body is accommodated inside the housing, wherein the compressor body includes a substantially columnar rotor that rotates together with a rotary shaft, a cylinder having an inner peripheral surface of an outline shape for surrounding the rotor from an outside of a peripheral surface thereof, a plurality of plate-shaped vanes provided to be able to project outward from the peripheral surface of the rotor, bearings that rotatably support the rotary shaft projecting from both end surfaces of the rotor, and side blocks that make contact with both end surfaces of the rotor and the cylinder to close both of the end surfaces, wherein a cylinder chamber is a space that is formed by an outer peripheral surface of the rotor, an inner peripheral surface of the cylinder and each inside surface of both of the side blocks for suction, compression and discharge of a gas.
The cylinder chamber, by configuring a projecting-side front end of each vane projecting from the outer peripheral surface of the rotor to be in contact with the inner peripheral surface of the cylinder, is defined into a plurality of compression chambers with the outer peripheral surface of the rotor, the inner peripheral surface of the cylinder and each inside surface of both of the side blocks, and the two vanes in tandem along a rotational direction of the rotor.
The outline shape of the inner peripheral surface of the cylinder is set such that an interval between the outer peripheral surface of the rotor and the inner peripheral surface of the cylinder changes for each rotary angle position of the rotor.
Specifically, the above-mentioned interval changes to be rapidly large from a small state in the upstream side in the rotational direction of the rotor, which corresponds to a stroke in which a volume of the compression chamber is enlarged with rotation of the rotor for the gas to be suctioned into the compression chamber through a suction portion.
Next, the interval is set in such a manner as to become gradually smaller toward the downstream side in the rotational direction of the rotor, which corresponds to a stroke in which a volume of the compression chamber decreases with rotation of the rotor for the gas in the compression chamber to be compressed.
Further, the interval is set to be further smaller in the downstream side in the rotational direction of the rotor, which corresponds to a stroke in which the gas compressed in the compression chamber with rotation of the rotor is discharged outside of the compression chamber through a discharge portion, and repetition of the suction stroke, the compression stroke, and the discharge stroke in this order enables a low-pressure gas suctioned from an outside of the compression chamber to be changed to a high-pressure gas for discharge (Japanese Patent Application Publication No. 54-28008).